Metabolic properties of lactobacilli in women experiencing recurring episodes of bacterial vaginosis with vaginal pH >or= 5.

While 60% of women experiencing recurring episodes of bacterial vaginosis (BV) with vaginal pH >or= 5 are depleted of resident probiotic lactobacilli, the remainder carry one or more strains of lactobacilli. Their ability to make D-lactic acid is, however, low (3.94 +/- 0.72 mM/L) compared to the D-lactic acid produced by strains from healthy vagina with vaginal pH approximately 4 (8.04 +/- 1.07 mM/L) culture supernatant of 0.5 McFarland concentration (P < 0.001).

Electronic structure of Mn-doped ZnO by x-ray emission and absorption spectroscopy.

We report an investigation of Mn-doped ZnO pellets with diluted Mn concentration by soft-x-ray emission and absorption spectroscopy. We have compared the electronic structure of two samples with different Mn concentration and different magnetic properties at room temperature: ferromagnetism in one case (Zn(0.98)Mn(0.02)O) and no magnetic order in the other (Zn(0.96)Mn(0.04)O). The results show that most of the Mn ions of the ferromagnetic sample are in the divalent state. For the nonmagnetic sample, a larger contribution of higher oxidation Mn states is present, which can be correlated to the suppressed ferromagnetism. The presence of oxygen atoms bonded to Mn ions and hybridized Mn 3d-O 2p states has been detected in both compounds. The partial density of states in the valence band has been measured with x-ray emission spectroscopy and the Mn 3d states have been found inside the bandgap of ZnO.

O K and Cu LIII edge study of itinerant holes in I2-, Hgl2- and HgBr2- intercalated BSCCO(2212) single crystals.

Intercalation effect on BSCCO (2212) system, although it increases the interlayer distance and the c-axis remarkably, produces only a small change in the transition temperature. Thus, amongst other things, intercalation provides an effective method to investigate the influence of the interblock coupling. Electrons are transferred from the host Cu-O2 layers to the guest molecules I2, HgBr2, HgI2 leading to evolution of the Tc. For this we have made high resolution XANES study on the O K and Cu L3 edges to estimate the density of the doping holes. We attempt on basis of our and earlier results the evolution of Tc in these as also the much larger decrease produced in Tc for I2-intercalation for which the increase in basal spacing is the smallest of the three halides.

Simultaneous measurement of XANES in halide-intercalated BSCCO(2212) using electron and fluorescence yield to compare their performance.

Total Yield with an escape depth of approximately 100-200 A is known to be rather surface sensitive. Fluorescence Yield, on the other hand, with an escape depth of approximately 1000-2000 A is relatively less prone to surface effects but necessitates some corrections to obtain the true signal. Both have their plus and minus points and, if used with care, yield reliable data. In the present experiment both the techniques have been simultaneously employed for measuring orientation dependent O K and the Cu L3 edges from an uncleaved surface of I(2)BSCCO(2212) single crystal to compare the performance of the two modes of detection. Despite glaring differences in intensities the results from the two appear to show reasonable agreement in respect of relative intensities of the spectral features.

Polarization-dependent XANES study of Bi2Sr2Ca(1-x)Pr(x)Cu2O8-delta insulating single crystal.

Pr doping has been extensively studied in cuprate superconductors to understand the mechanism of quenching of superconductivity in cuprate perovskites. Experience has revealed that it acts differently in different cuprate perovskites. We have made high resolution polarization XANES measurements on a Pr-doped single crystal within the ab-plane on the Cu K and Pr L III absorption edges to ascertain the valence state of Pr cation and thereby try learning how it is quenching superconductivity in the present case. Our results show that besides the Pr quenching holes the possibility of its localizing some holes through hybridization with O 2p and Cu 3d cannot be ruled out.